我在Delphi中使用弹出菜单.我希望以“无线电组”的方式使用它,如果用户选择了一个项目,则检查它并且不检查其他项目.我尝试使用Autocheck属性,但这允许检查多个项目.有没有办法设置弹出菜单,以便只能检查一个项目?
解决方法
Zartog是正确的,但是如果要保留复选框,请将此事件分配给弹出菜单中的每个项目.
请注意,此代码有点毛茸茸,因为它不依赖于知道弹出菜单的名称(因此,使用“GetParentComponent”查找).
- procedure TForm2.OnPopupItemClick(Sender: TObject);
- var
- i : integer;
- begin
- with (Sender as TMenuItem) do begin
- //if they just checked something...
- if Checked then begin
- //go through the list and *un* check everything *else*
- for i := 0 to (GetParentComponent as TPopupMenu).Items.Count - 1 do begin
- if i <> MenuIndex then begin //don't uncheck the one they just clicked!
- (GetParentComponent as TPopupMenu).Items[i].Checked := False;
- end; //if not the one they just clicked
- end; //for each item in the popup
- end; //if we checked something
- end; //with
- end;
您可以在运行时将事件分配给表单上的每个弹出框(如果您想这样做):
- procedure TForm2.FormCreate(Sender: TObject);
- var
- i,j: integer;
- begin
- inherited;
- //look for any popup menus,and assign our custom checkBox handler to them
- if Sender is TForm then begin
- with (Sender as TForm) do begin
- for i := 0 to ComponentCount - 1 do begin
- if (Components[i] is TPopupMenu) then begin
- for j := 0 to (Components[i] as TPopupMenu).Items.Count - 1 do begin
- (Components[i] as TPopupMenu).Items[j].OnClick := OnPopupItemClick;
- end; //for every item in the popup list we found
- end; //if we found a popup list
- end; //for every component on the form
- end; //with the form
- end; //if we are looking at a form
- end;
回答此答案下方的评论:如果您要求至少检查一个项目,请使用此项目代替第一个代码块.您可能希望在oncreate事件中设置默认选中的项目.
- procedure TForm2.OnPopupItemClick(Sender: TObject);
- var
- i : integer;
- begin
- with (Sender as TMenuItem) do begin
- //go through the list and make sure *only* the clicked item is checked
- for i := 0 to (GetParentComponent as TPopupMenu).Items.Count - 1 do begin
- (GetParentComponent as TPopupMenu).Items[i].Checked := (i = MenuIndex);
- end; //for each item in the popup
- end; //with
- end;